Process of making pistons



I J. FLAMMANG.

PROCESS OF MAKING PISTONS.

APPLICATION .HLED MAY 23.1918

0 2 H n 7 2 W i T u A W 4 F m a m a E I E E E 1 E w 71 4 E 7 E 4 5\ 8 I 1 n r or.

J57??? I digit v'Il'OI-IN' FLAMMANG, OF ST. LOUIS, MISSOURI, ASSIGNOR PATENT OFFICE.

T0 OTTMAR G. STARK, OF ST.

LOUIS, MISSOURI.

PROCESS OF MAKING PISTONS.

Application filed May 23, 1918.

To all whom it may concern:

Be it known that I, JOHN FLAMMANG, a citizen of the United States, residing at St. Louis, Missouri, have invented a new and useful Process of Making Pistons, of which the following is a specification.

This invention relates to the art of manufacturing pistons.

An object of the invention is to improve the art of manufacturing pistons whereby pistons may be produced to utilize the resiliency of the metal of which the pistons are composed in an efficient manner in order to maintain close contact with the cylinder walls making use of piston rings or packing unnecessary.

A specific object of the invention is to provide a method for use in the manufacture of pistons, whereby the upper portions of the pistons will cooperate effectively with the cylinder to prevent the passage of-gas, steam or the like between the piston and the cylinder without the use of piston rings or packing.

Other objects will be apparent by the fol lowing description in which reference is made to the accompanying drawings, illustrating a piston in several stages of its con struction in accordance with the present invention, and in which- Figure l is an elevation partly in section illustrating a casting the construction of the Fig. 2 is an elevation ing after one or-more treatment.

Fig. 3 isa view of the casting after; the upper portion thereof has been expanded or placed undertension and set in its expanded shape, so thatwhen the piston is finished and placed in the cylinder it will impart pressure against the cylinder wall all around. p

Fig. 4 is a view of the piston body while the upperportion thereof above the wrist pin is held under tensionready for the casting to be finished as surface, tensioning of piston body. illustrating the caststages or steps of the lower portion of the piston body being prevented by the wrist pin; 7 p

Fig.5 is a view illustrating the piston body held under tension within the cylinder in which the treatment of the body of the piston is finished and made ready for the head plate to be applied thereto.

' Specification of Letters Patent.

- uppenportion of the .panded piston leaving the that may be used in to its circumferential,

Patented July 20, 1920. Serial No. 236,189.

F ig. 6 is an elevation of a finished piston made in accordance with my present invention.

Fig. 7 is a sectional view of a mounted within a cylinder.

By my present invention the body of the piston is made from a casting so that the casting in its finished form is expanded from its original size to asize in excess of the diameter of the cylin der for which the piston is intended; and then compressed and placed under tension and finished to a size equal to the size of the cylinder for which it is intended so that when the piston body is placed within the cylmder it will impart pressure against the wall of the cylinder all around, thus dispensing with the use of piston rings and packing. The upper portion of the piston is set in its expanded shape by heat, or in any other desired manner as by hammering, and the wrist pin is mounted in the exupper portion of piston the piston free to expand cooperate properly with cylinder. As shown, the piston body is composed of a lower ring 1', an upper ring 2, connections 3 integrally uniting the upper and lower rings and bosses 4 integral with the connections 3. The original casting is provided with arms 5 extending inwardly from diametrically opposite sides above the plane of the bosses 4. I Projections 6 are integral with the arms 5 and are spaced apart so that they may be .capable of movement toward each other when the upper ring is compressed as hereinafter explained. I

The first stages or steps in the construction of the piston by my improved process consist in cutting the upper ring as shown at 7 so as to divide the upper ring into separate segmental sections which are adapted to press against the wall of the cylinder in which the piston operates by the resiliency of themetal of the piston. After the upper ring has been cut or split into segmental sections the upper portion of the piston body is spread apartand placed under tension in any desiredmanner, as by inserting a wedge or. block v8, or other appropriate form of implement, between the bosses 4. Next the material ofthe piston is set in its expanded shape by subjecting the piston body to heat 'or by hammering so that the molecular the wall of the and contract and body is subjected.

' holes in the extensions structure is changed. As a result of such treatment after the spacer 8 1s removed the material will be held in its new shape, be-

cause of the treatment to which the piston After the spacer 8 is removed alined holes 9 are formed through the connections 3 and the bosses i and the wrist pin 10 is mounted in the holes thus formed and is'held in such position by set screws 11'.

Next pin and the segmental sections of the ring 2 are placed under tension. This may be effected as shown by inserting a bolt 12 in 6 and turning the nut on the bolt until the segmental sections of the ring 2 are turned to the desired positions and the proper tension is given to the connections 3 above the wrist pin. While the casting is thus held under tension the periphery of the casting is ground or turned and finished to a sizein which thelower portion of the casting is of slightly less di ameter than the diameter of the cylinder for which the piston is intended and in which the diameter of the ring 2 while under compression or tension is of ,a size equal to the diameter of the cylinder for which the piston is intended. 'The dottedlines 13 (Fig. 4:) approximately indicate the surface lines to which the piston is to be finished.

After the periphery of the piston has been finished to give the upper ring a diameter the same as the diameter of the cylinder for which the piston is intended, while the .ma-

terial is held under tension as described, the piston is placed within a-cylinder 14 (Fig.

5) of the same diameter as the diameter of the cylinder for which the piston is intended, thus holding the upper portion of the piston compressed under tension after the bolt 12 is removed.

' The upper portion of the ring 2 is then cut away'below the arms 5 at right angles to the axis of the piston and, if desired, an internal groove 15 is formed in the ring 2. Also, either before the piston is placed within the, cylinder 14- or after removal therefrom, as desired, a number of circumferential grooves 16 are formed in the lower ring 1, thesame being adapted to receive an oil or lubricant whereby the piston and the cylinder wall are lubricated during operation of the piston. j V

The head or top plate 17 is connected to the ring 2 and interlocked therewith in some desired manner, as by a flange 18 engaging in the groove 15; or, as preferred, by keys 19 seated in slots in the open ends of the ring 2 and engaging ingrooves in the top plate; or, if desired both the flanges 18 and the keys 19 may be. employed as shownin Fig. 7 Said'keystherefore are effective to hold the topplate in connection with the piston body and, since the keys exupward movement of the the connectionsB above the wrist.

tend across the slits 7 said keys are also effective to close the spaces between the open ends of the ring 2 and thus prevent passage of gas through said spaces.

The upperedge of the ring 1 is beveled to provide a scraping edge 20, which will scrape, the oil from the cylinder wall during piston; and the lower edge of the ring 2 is beveled to provide a scraping edge 21 to scrape theoil from the cylinder wall during downward move-' ment of the piston. 7

As clearly illustrated in Figs. 6 and 7, the finished piston has a body composed of an upper ring of slightly larger diameter than the diameter of the cylinder for which the piston is intended; and. when the piston body is compressed within the cylinder the segmental sections of the upper ring will impart aga nst the cylinder wall all around sufiicient pressure to prevent the passage of gas or steam while the spaces between the ends of the segmental sections of the upper ring are closed against the passage of gas 7 or steam by the keys 19.

Plainly the order in which many of the stages of treatment are'performed in the manufacture ofthe piston is not of great importance and the order .of such performance may be varied in many particulars without departure from the principle of the invention as set forth in the appended claims.

I claim: p q 1. The processof making. a piston which consists in forming a piston body with an upper ring and a. lower ring which are integrally united; splitting the upperring to form segmental sections; expanding the upper portion of the piston body; treating the piston body to set the material in its expanded shape; compressing the expanded portion of the piston body; and finishing the same while undercompression.

2. The process of making a piston which consists in forming apiston body with an ice upper ring and a lower ring which are integrally un ted; splitting the upper ring to form segmental sections;fexpanding the upper portion of the pistonbodyjtreating the piston body to set thematerial in its ex panded shape; compressing theexpanded portion of the piston body; and finishing the same while under compression to a diameter equal to the diameter ofthe cylinder for which the piston is intended.

3. The process of making a piston which consists in splittingthe upper end of apis- 7 ton body into segmental sections, expanding the segmentaltsections ;setting the material in its expanded shape; and finishing the segmental sections to a sizeso that when the piston is placed within a cylinder the segmental sections will press outwardly in all directions against the cylinder wall; V

7 ing the upper ring under 5. The process of forming a piston which consists in forming a piston body of a lower ring, and an upper ring integrally connected with the lower ring; splitting the upper ring into segmental sections; holding the material under tension; treating the material to set the same in its tensioned shape; compressing the upper'ring under tension after said treatment; and finishing the piston while the same is compressed under tension. 7

6. The process of forming a piston which consists in forming a piston body of a lower ring, and an upper ring integrally connected with the lower ring; splitting the upper ring into segmental sections; holding the material under tension; treating the material to set the same in its tensioned shape; compresstension after said treatment; and finishing the piston while the same is compressed under tension to a size in which the upper ring is of the same diameter as the diameter of the cylinder for which the piston is intended.

7. The process of forming a piston which consists in forming a piston body of a lower ring, and an upper ring integrally connected with the lower ring; splitting the upper ring into segmental sections; holding the material under tension; treating the material to set the same in its tensioned shape; compressing the upper ring under tension after said treatment; finishing the piston while the same is compressed under tension to a size in which the upper ring is of the same diameter as the diameter of the cylinder for which the piston is intended; and connecting a top plate to the piston body.

8. The process of forming a piston which consists of forming a piston body of a lower ring and an upper ring, and integral connections uniting the upper and lower rings; splitting the upper ring intosegmental sections mechanically forcing said connections apart to place them under tension; heating the piston body to set the material in its changed shape; forcing the segmental sections of the upper ring toward each other to place the material under tension; and finishing the piston.

9. The process of forming a piston which consists of forming a piston body of a lower ring, an upper ring and integral connections uniting the upper and lower rings; splitting the upper ring into segmental sections; mechanically forcing said connections apart to place them under tension; heating the piston body to set the material'in its changed shape; forming alined holes through said connections after the same have been subjected to heat; fixing a wrist pin in said holes; mechanically drawing the segmental sections of the upper ring toward each other to place the material thereof under tension; and. finishing the piston.

JOHN FLAMMANG. 

